The present invention relates to a composition for a resist underlayer film and a method for producing the same. More particularly, the present invention relates to a composition for a resist underlayer film excellent in reproducibility of a resist pattern, excellent in adhesion to a resist, excellent in resistance to a developing solution used after exposure of the resist and decreased in film loss in oxygen ashing of the resist, and a method for producing the same.
In pattern formation of semiconductor elements, minute processing of organic materials and inorganic materials is carried out by lithography techniques, resist development processes and pattern transfer after the resist development.
However, with the progress of high integration of semiconductor elements, it becomes difficult to accurately transfer patterns to resists in exposure processes, sometimes resulting in wrong processing dimensions in substrate processing processes. Then, anti-reflection films for reducing the influence of standing waves contributing to the wrong processing dimensions become indispensable in minute processing processes. Such anti-reflection films include underlayer anti-reflection films formed between resists and substrates.
On the other hand, when substrates such as silicon oxide films are processed, resist patterns are used as masks. The resist film thickness decreases with miniaturization, so that the masking property of the resists becomes insufficient. It becomes therefore difficult to process the substrates without damaging them. Then, a process is employed in which a resist pattern is first transferred to an underlayer film for processing a substrate, followed by dry etching of the substrate using the underlayer film as a mask. The term xe2x80x9cunderlayer film for processing the substratexe2x80x9d means a film also serving as the underlayer anti-reflection film or a film formed under the anti-reflection film. In this process, the etching rate of the resist is close to that of the underlayer film for processing the substrate. It is therefore necessary to form a mask for processing the underlayer film (a resist underlayer film) between the resist and t e underlayer film. That is to say, a multilayer film composed of the underlayer film for processing the substrate, the resist underlayer film and the resist is formed on the substrate.
The characteristics required for the resist underlayer films are that the resist patterns having no footing can be formed, that the resist underlayer films are excellent in adhesion to the resists, and that when the underlayer films for processing the substrates are processed, the resist underlayer films have the sufficient masking property. However, materials meeting all of these requirements have not been discovered yet.
An object of the invention is to provide a composition for a resist underlayer film which is not separated from a resist, improves the reproducibility of a resist pattern, and has the resistance to oxygen ashing in removing an alkali and the resist by providing the resist underlayer film under the resist for solving the problems described above.
Another object of the invention is to provide a method for producing the above-mentioned composition.
According to the invention, there is provided a composition for a resist underlayer film comprising:
both or either of a hydrolysate and a condensate of (A) at least one compound (hereinafter referred to as compound (1)) selected from the group consisting of (A-1) a compound represented by the following general formula (1):
R1aSi(OR2)4xe2x88x92axe2x80x83xe2x80x83(1)
wherein R1 represents a hydrogen atom, a fluorine atom or a univalent organic group, R2 represents a univalent organic group, and a represents an integer of 0 to 2, and (A-2) a compound represented by the following general formula (2):
R2b(R4O)3xe2x88x92bSixe2x80x94(R7)dxe2x80x94Si(OR5)3xe2x88x92cR6cxe2x80x83xe2x80x83(2)
wherein R3, R4, R5 and R6, which may be the same or different, each represent univalent organic groups, b and c, which may be the same or different, each represent integers of 0 to 2, R7 represents an oxygen atom or xe2x80x94(CH2)nxe2x80x94, d represents 0 or 1, and n represents an integer of 1 to 6; and
(B) a compound generating an acid by ultraviolet irradiation and/or heating (hereinafter referred to as an xe2x80x9cacid generating agentxe2x80x9d).
The invention further provides a method for producing the composition described above.
Component (A-1)
In the above-mentioned general formula (1), the univalent organic groups represented by R1 and R2 include alkyl, aryl, allyl and glycidyl groups. Further, in general formula (1), R1 is preferably a univalent organic group, particularly an alkyl or phenyl group.
Here, the alkyl groups include methyl, ethyl, propyl and butyl, and each preferably has 1 to 5 carbon atoms. These alkyl groups may be straight-chain or branched, or hydrogen atoms may be substituted by fluorine atoms.
In general formula (1), the aryl groups include phenyl, naphthyl, methylphenyl, ethylphenyl, chlorophenyl, bromophenyl and fluorophenyl.
Specific examples of the compounds represented by general formula (1) include trimethoxysilane, triethoxy-silane, tri-n-propoxysilane, tri-iso-propoxysilane, tri-n-butoxysilane, tri-sec-butoxysilane, tri-tert-butoxysilane, triphenoxysilane, fluorotrimethoxysilane, fluorotriethoxysilane, fluorotri-n-propoxysilane, fluorotri-iso-propoxysilane, fluorotri-n-butoxysilane, fluorotri-sec-butoxysilane, fluorotri-tert-butoxysilane, fluorotriphenoxy-silane, tetramethoxysilane, tetraethoxysilane, tetra-n-propoxysilane, tetra-iso-propoxysilane, tetra-n-butoxy-silane, tetra-sec-butoxysilane, tetra-tert-butoxysilane, tetraphenoxysilane, methyltrimethoxysilane, methyltri-ethoxysilane, methyltri-n-propoxysilane, methyltri-iso-propoxysilane, methyltri-n-butoxysilane, methyltri-sec-butoxysilane, methyltri-tertbutoxysilane, methyltri-phenoxysilane, ethyltrimethoxysilane, ethyltriethoxysilane, ethyltri-n-propoxysilane, ethyltriiso-propoxysilane, ethyltri-n-butoxysilane, ethyltri-sec-butoxysilane, ethyl-tri-tert-butoxysilane, ethyltriphenoxysilane, vinyltri-methoxysilane, vinyltriethoxysilane, vinyltri-n-propoxy-silane, vinyltriiso-propoxysilane, vinyltri-n-butoxy-silane, vinyltri-sec-butoxysilane, vinyltri-tert-butoxy-silane, vinyltriphenoxysilane, n-propyltrimethoxysilane, n-propyltriethoxysilane, n-propyltri-n-propoxysilane, propyltri-iso-propoxysilane, n-propyltri-n-butoxysilane, n-propyltri-sec-butoxysilane, n-propyltri-tert-butoxy-silane, n-propyltriphenoxysilane, i-propyltrimethoxysilane, i-propyltriethoxysilane, i-propyltri-n-propoxysilane, i-propyltri-iso-propoxysilane, i-propyltri-n-butoxysilane, propyltri-sec-butoxysilane, i-propyltri-tert-butoxy-silane, i-propyltriphenoxysilane, n-butyltrimethoxysilane, n-butyltriethoxysilane, n-butyltri-n-propoxysilane, butyltri-iso-propoxysilane, n-butyltri-n-butoxysilane, n-butyltri-sec-butoxysilane, n-butyltri-tert-butoxysilane, n-butyltriphenoxysilane, sec-butyltrimethoxysilane, sec-butyl-i-triethoxysilane, sec-butyltri-n-propoxysilane, sec-butyltri-iso-propoxysilane, sec-butyltri-n-butoxy-silane, sec-butyltri-sec-butoxysilane, sec-butyltri-tertbutoxysilane, sec-butyltriphenoxysilane, t-butyltrimethoxysilane, t-butyltriethoxysilane, t-butyltri-n-propoxysilane, t-butyltri-iso-propoxysilane, t-butyltri-n-butoxysilane, t-butyltri-sec-butoxysilane, t-butyltri-tertbutoxysilane, t-butyltriphenoxysilane, phenyltrimethoxysilane, phenyltriethoxysilane, phenyltri-n-propoxysilane, phenyltri-iso-propoxysilane, phenyltri-n-butoxysilane, phenyltri-sec-butoxysilane, phenyltri-tert-butoxysilane, phenyltriphenoxysilane, vinyltrimethoxysilane, vinyltriethoxysilane, xcex3-aminopropyltrimethoxysilane, xcex3-aminopropyltriethoxysilane, xcex3-glycidoxypropyltrimethoxysilane, xcex3-glycidoxypropyltriethoxysilane, xcex3-trifluoropropyltrimethoxysilane, xcex3-trifluoropropyltriethoxysilane, dimethyldimethoxysilane, dimethyldiethoxysilane, dimethyldi-n-propoxysilane, dimethyl-di-iso-propoxysilane, dimethyl-di-n-butoxysilane, dimethyl-di-sec-butoxysilane, dimethyl-di-tert-butoxysilane, dimethyldiphenoxysilane, diethyldimethoxysilane, diethyldiethoxysilane, diethyl-di-n-propoxysilane, diethyl-di-iso-propoxysilane, diethyl-di-n-butoxysilane, diethyl-di-sec-butoxysilane, diethyl-ditert-butoxysilane, diethyldiphenoxysilane, di-n-propyldimethoxysilane, di-n-propyldiethoxysilane, di-n-propyldi-n-propoxysilane, di-n-propyldi-iso-propoxysilane, di-n-propyldi-n-butoxysilane, di-n-propyldi-sec-butoxysilane, di-n-propyldi-tert-butoxysilane, di-n-propyldiphenoxysilane, di-iso-propyldimethoxysilane, di-iso-propyldiethoxysilane, di-iso-propyldi-n-propoxysilane, di-iso-propyldi-iso-propoxysilane, di-iso-propyldi-n-butoxy-silane, di-iso-propyldi-sec-butoxysilane, di-iso-propyldi-tert-butoxysilane, di-iso-propyldiphenoxysilane, di-n-butyldimethoxysilane, di-n-butyldiethoxysilane, di-n-butyldi-n-propoxysilane, di-n-butyldi-iso-propoxysilane, di-n-butyldi-n-butoxysilane, di-n-butyldi-sec-butoxy-silane, di-n-butyldi-tert-butoxysilane, di-n-butyldi-phenoxysilane, di-sec-butyldimethoxysilane, di-sec-butyl-diethoxysilane, di-sec-butyldi-n-propoxysilane, di-sec-butyldi-iso-propoxysilane, di-sec-butyldi-n-butoxysilane, di-sec-butyldi-sec-butoxysilane, di-sec-butyldi-tert-butoxysilane, di-sec-butyldiphenoxysilane, di-tert-butyl-dimethoxysilane, di-tert-butyl-diethoxysilane, di-tert-butyldi-n-propoxysilane, di-tert-butyldi-iso-propoxysilane, di-tert-butyldi-n-butoxysilane, di-tert-butyldi-sec-butoxysilane, di-tert-butyldi-tert-butoxysilane, di-tert-butyldiphenoxysilane, diphenyldi-methoxysilane, diphenyldiethoxysilane, diphenyldi-n-propoxysilane, diphenyldi-iso-propoxysilane, diphenyldi-n-butoxysilane, diphenyldi-sec-butoxysilane, diphenyldi-tert-butoxysilane, diphenyldiphenoxysilane, divinyltri-methoxysilane, trimethylmonomethoxysilane, trimethylmono-ethoxysilane, triethylmonomethoxysilane, triethylmono-ethoxysilane, triphenylmonomethoxysilane and triphenyl-monoethoxysilane.
Preferred examples of these compounds include tetramethoxysilane, tetraethoxysilane, tetra-n-propoxysilane, tetra-iso-propoxysilane, tetraphenoxysilane, methyltrimethoxysilane, methyltriethoxysilane, methyltri-n-propoxysilane, methyltri-iso-propoxysilane, ethyltrimethoxysilane, ethyltriethoxysilane, vinyltrimethoxysilane, vinyltriethoxysilane, phenyltrimethoxysilane, phenyltriethoxysilane, dimethyldimethoxysilane, dimethyldiethoxysilane, diethyldimethoxysilane, diethyldiethoxysilane, diphenyldimethoxysilane, diphenyldiethoxysilane, trimethylmonomethoxysilane, trimethylmonoethoxysilane, triethylmonomethoxysilane, triethylmonoethoxysilane, triphenylmonomethoxysilane and triphenylmonoethoxysilane.
They may be used alone or in combination.
Component (A-2)
In the above-mentioned general formula (2), the univalent organic groups include organic groups similar to those previously defined in general-formula (1).
Of the compounds represented by general formula (2), the compounds in which R7 is an oxygen atom include hexamethoxydisiloxane, hexaethoxydisiloxane, hexaphenoxydisiloxane, 1,1,1,3,3-pentamethoxy-3-methyldisiloxane, 1,1,1,3,3-pentaethoxy-3-methyldisiloxane, 1,1,1,3,3-pentamethoxy-3-phenyldisiloxane, 1,1,1,3,3-pentaethoxy-3-phenyldisiloxane, 1,1,3,3-tetramethoxy-1,3-dimethyldisiloxane, 1,1,3,3-tetraethoxy-1,3-dimethyldisiloxane, 1,1,3,3-tetramethoxy-1,3-diphenyldisiloxane, 1,1,3,3-tetraethoxy-1,3-diphenyl-disiloxane, 1,1,3-trimethoxy-1,3,3-trimethyldisiloxane, 1,1,3-triethoxy-1,3,3-trimethyldisiloxane, 1,1,3-tri-methoxy-1,3,3-triphenyldisiloxane, 1,1,3-tri-ethoxy-1,3,3-triphenyldisiloxane, 1,3-dimethoxy-1,1,3,3-tetramethyldisiloxane, 1,3-diethoxy-1,1,3,3-tetramethyldisiloxane, 1,3-dimethoxy-1,1,3,3-tetraphenyldisiloxane and 1,3-diethoxy-1,1,3,3-tetraphenyldisiloxane. Preferred examples of these compounds include hexamethoxydisiloxane, hexaethoxydisiloxane, 1,1,3,3-tetramethoxy-1,3-dimethyldisiloxane, 1,1,3,3-tetraethoxy-1,3-dimethyldisiloxane, 1,1,3,3-tetramethoxy-1,3-diphenyldisiloxane, 1,3-dimethoxy-1,1,3,3-tetramethyldisiloxane, 1,3-diethoxy-1,1,3,3-tetramethyldisiloxane, 1,3-dimethoxy-1,1,3,3-tetraphenyldisiloxane and 1,3-diethoxy-1,1,3,3-tetraphenyldisiloxane.
The compounds in which d is 0 in general formula (2) include hexamethoxydisilane, hexaethoxydisilane, hexaphenoxydisilane, 1,1,1,2,2-pentamethoxy-2-methyldisilane, 1,1,1,2,2-pentaethoxy-2-methyldisilane, 1,1,1,2,2-pentamethoxy-2-phenyldisilane, 1,1,1,2,2-pentaethoxy-2-phenyldisilane, 1,1,2,2-tetramethoxy-1,2-dimethyldisilane, 1,1,2,2-tetraethoxy-1,2-dimethyldisilane, 1,1,2,2-tetramethoxy-1,2-diphenyldisilane, 1,1,2,2-tetraethoxy-1,2-diphenyldisilane, 1,1,2-trimethoxy-1,2,2-trimethyldisilane, 1,1,2-triethoxy-1,2,2-trimethyldisilane, 1,1,2-trimethoxy-1,2,2-triphenyldisilane, 1,1,2-triethoxy-1,2,2-triphenyldisilane, 1,2-dimethoxy-1,1,2,2-tetramethyldisilane, 1,2-diethoxy-1,1,2,2-tetramethyldisilane, 1,2-dimethoxy-1,1,2,2-tetraphenyldisilane and 1,2-diethoxy-1,1,2,2-tetraphenyldisilane. The compounds in which R7 is xe2x80x94(CH2)nxe2x80x94 in general formula (2) include bis(hexamethoxysilyl)methane, bis(hexaethoxysilyl)methane, bis(hexaphenoxysilyl)methane, bis(dimethoxymethylsilyl)methane, bis(diethoxymethylsilyl)methane, bis(dimethoxyphenylsilyl)methane, bis(diethoxyphenylsilyl)methane, bis(methoxydimethylsilyl)methane, bis(ethoxydimethylsilyl)methane, bis(methoxydiphenylsilyl)methane, bis(ethoxydiphenylsilyl)methane, bis(hexamethoxysilyl)ethane, bis(hexaethoxysilyl)ethane, bis(hexaphenoxysilyl)ethane, bisdimethoxymethylsilyl)ethane, bis(diethoxymethylsilyl)ethane, bis(dimethoxyphenylsilyl)ethane, bis(diethoxyphenylsilyl)ethane, bis(methoxydimethylsilyl)ethane, bis(ethoxydimethylsilyl)ethane, bis(methoxydiphenylsilyl)ethane, bis(ethoxydiphenylsilyl)ethane, 1,3-bis(hexamethoxysilyl)propane, 1,3-bis(hexaethoxysilyl)propane, 1,3-bis(hexaphenoxysilyl)propane, 1,3-bis(dimethoxymethylsilyl)propane, 1,3-bis(diethoxymethylsilyl)propane, 1,3-bis(dimethoxyphenylsilyl)propane, 1,3-bis(diethoxyphenylsilyl)propane, 1,3-bis(methoxydimethylsilyl)propane, 1,3-bis(ethoxydimethylsilyl)propane, 1,3-bis(methoxydiphenylsilyl)propane and 1,3-bis(ethoxydiphenylsilyl)propane. Preferred examples of these compounds include hexamethoxydisilane, hexaethoxydisilane, hexaphenoxydisilane, 1,1,2,2-tetramethoxy-1,2-dimethyldisilane, 1,1,2,2-tetraethoxy-1,2-dimethyldisilane, 1,1,2,2-tetramethoxy-1,2-diphenyldisilane, 1,1,2,2-tetraethoxy-1,2-diphenyldisilane, 1,2-dimethoxy-1,1,2,2-tetramethyldisilane, 1,2-diethoxy-1,1,2,2-tetramethyldisilane, 1,2-dimethoxy-1,1,2,2-tetraphenyldisilane, 1,2-diethoxy-1,1,2,2-tetraphenyldisilane, bis(hexamethoxysilyl)methane, bis(hexaethoxysilyl)methane, bis(dimethoxymethylsilyl)methane, bis(diethoxymethylsilyl)methane, bis(dimethoxyphenylsilyl)methane, bis(diethoxyphenylsilyl)methane, bis(methoxydimethylsilyl)methane, bis(ethoxydimethylsilyl)methane, bis(methoxydiphenylsilyl)methane and bis(ethoxydiphenylsilyl)methane.
In the invention, the above-mentioned components (A-1) and (A-2), or either of them is used as component (A). The compounds of each of components (A-1) and (A-2) can be used as a combination of two or more of them.
In the invention, component (A) is preferably (1) or (2) described below, and particularly preferably (2) in that the adhesion to a resist is better.
(1) Both or either of a hydrolysate and a condensate of a compound (hereinafter referred to as compound (a1)) represented by the following general formula (3):
Si(OR2)4xe2x80x83xe2x80x83(3)
wherein R2 represents a univalent organic group, and specific examples thereof are the same as with the above-mentioned general formula (1).
(2) both or either of a hydrolysate and a condensate of a silane composition comprising a compound represented by the above-mentioned general formula (3) and a compound (hereinafter referred to as compound (a2)) represented by the following general formula (4):
R1nSi(OR2)4xe2x88x92nxe2x80x83xe2x80x83(4)
wherein R1 and R2, which may be the same or different, each represent univalent organic groups, specific examples thereof are the same as with general formula (1), and n represents an integer of 1 to 3.
In the case of (2) described above, the amount of compound (a2) (in terms of a completely hydrolyzed and/or condensed product) is from 0.5 part to 50 parts by weight, and more preferably from 5 part to 40 parts by weight, based on 100 parts by weight of compound (a1) (in terms of a completely hydrolyzed and/or condensed product).
Particularly preferred examples of compounds (a1) include tetramethoxysilane and tetraethoxysilane. Particularly preferred examples of compounds (a2) include methyltrimethoxysilane, methyltriethoxysilane, dimethyldimethoxysilane and di-methyldiethoxysilane.
When compound (1) is hydrolyzed and/or partially condensed, water is preferably used in an amount of 0.25 mole to 3 moles, particularly 0.3 mole to 2.5 moles, per mole of group represented by R1Oxe2x80x94, R4Oxe2x80x94 or R5Oxe2x80x94. When the amount of water added is within the range of 0.3 mole to 2.5 moles, there is no fear of decreased uniformity of a coating film, and the storage stability of the composition for the resist underlayer film is less likely to deteriorate.
Specifically, water is added intermittently or continuously to an organic solvent in which compound (1) has been dissolved. In this case, a catalyst may be either previously added to the organic solvent, or dissolved or dispersed in the water in adding the water. In this case, the reaction temperature is usually from 0xc2x0 C. to 100xc2x0 C., and preferably from 15xc2x0 C. to 80xc2x0 C. Then, component (B) is added to the solution thus obtained, thereby providing the composition for the resist underlayer film of the invention.
Further, when two or more compounds are used as compound (1), (a) two or more compounds may be mixed, followed by hydrolysis and/or condensation, or (b) two or more compounds may be each separately hydrolyzed and/or condensed, followed by mixing. In particular, (b) is preferred.
Particularly, when compound (a2) is used, following two using methods are preferred.
(2-1) both or either of a hydrolysate and a condensate of a compound (a1) and both or either of a hydrolysate and a condensate of a compound (a2) are mixed to use.
(2-2) both or either of a hydrolysate and a condensate of a compound (a1) and both or either of a hydrolysate and a condensate (a co-hydrolysate and a co-condensate) obtained from mixing compound (a1) and compound (a2), followed by hydrolysis and condensation of the mixture, are mixed to use.
Further, when compound (1) is hydrolyzed and/or partially condensed, a catalyst may be used. The catalysts used in this case include metal chelate compounds, organic acids, inorganic acids, organic bases and inorganic bases.
The metal chelate compounds include compounds represented by the following general formula (6):
R11fM(OR12)gxe2x88x92fxe2x80x83xe2x80x83(6)
wherein R11 indicates a chelating agent, M indicates a metal atom, R12 indicates an alkyl group having 2 to 5 carbon atoms or an aryl group having 6 to 20 carbon atoms, g represents a valence of the metal atom M, and f represents an integer of 1xe2x88x92g.
Above all, chelate compounds of titanium, aluminum or zirconium are preferred. Specific examples thereof include titanium chelate compounds such as triethoxy.mono(acetylacetonato)titanium, tri-n-propoxy.mono(acetylacetonato)titanium, tri-i-propoxy.mono(acetylacetonato)titanium, tri-n-butoxy.mono(acetylacetonato)-titanium, tri-sec-butoxy.mono(acetylacetonato)titanium, tri-t-butoxy.mono(acetylacetonato)titanium, diethoxy.bis(acetylacetonato)titanium, di-n-propoxy.bis(acetylacetonato)titanium, di-i-propoxy.bis(acetylacetonato)titanium, di-n-butoxy.bis(acetylacetonato)titanium, di-sec-butoxy.bis(acetylacetonato)titanium, di-t-butoxy.bis-(acetylacetonato)titanium, monoethoxy.tris(acetylacetonato)titanium, mono-n-propoxy.tris(acetylacetonato)titanium, mono-i-propoxy.tris(acetylacetonato)titanium, mono-n-butoxy.tris(acetylacetonato)titanium, mono-sec-butoxy.tris(acetylacetonato)titanium, mono-t-butoxy.tris(acetylacetonato)titanium, tetrakis(acetylacetonato)titanium, triethoxy.mono(ethylacetoacetate)titanium, tri-n-propoxy.mono(ethylacetoacetate)titanium, tri-i-propoxy.mono(ethylacetoacetate)titanium, tri-n-butoxy.mono(ethylacetoacetate)titanium, tri-sec-butoxy.mono(ethylacetoacetate)titanium, tri-t-butoxy.mono(ethylacetoacetate)titanium, diethoxy.bis(ethylacetoacetate)titanium, di-n-propoxy.bis(ethylacetoacetate)titanium, di-i-propoxy.bis(ethylacetoacetate)titanium, di-n-butoxy.bis(ethylacetoacetate)titanium, di-sec-butoxy.bis(ethylacetoacetate)titanium, di-t-butoxy.bis(ethylacetoacetate)titanium, monoethoxy.tris(ethylacetoacetate)titanium, mono-n-propoxy.tris(ethylacetoacetate)titanium, mono-i-propoxy.tris(ethylacetoacetate)titanium, mono-n-butoxy.tris(ethylacetoacetate)titanium, mono-sec-butoxy.tris(ethylacetoacetate)titanium, mono-t-butoxy.tris(ethylacetoacetate)titanium, tetrakis(ethylacetoacetate)-titanium, mono(acetylacetonato)tris(ethylacetoacetate)-titanium, bis(acetylacetonato)bis(ethylacetoacetate)-titanium and tris(acetylacetonato)mono(ethylacetoacetate)-titanium; zirconium chelate compounds such as triethoxy.mono(acetylacetonato)zirconium, tri-n-propoxy.mono(acetylacetonato)zirconium, tri-i-propoxy.mono(acetylacetonato)zirconium, tri-n-butoxy.mono(acetylacetonato)zirconium, tri-sec-butoxy.mono(acetylacetonato)zirconium, tri-t-butoxy.mono(acetylacetonato)zirconium, diethoxy.bis(acetylacetonato)zirconium, di-n-propoxy.bis(acetylacetonato)zirconium, di-i-propoxy.bis(acetylacetonato)zirconium, di-n-butoxy.bis(acetylacetonato)zirconium, di-sec-butoxy.bis(acetylacetonato)zirconium, di-t-butoxy.bis(acetylacetonato)zirconium, monoethoxy.tris(acetylacetonato)zirconium, mono-n-propoxy.tris(acetylacetonato)zirconium, mono-i-propoxy.tris(acetylacetonato)zirconium, mono-n-butoxy.tris(acetylacetonato)zirconium, mono-sec-butoxy.tris(acetylacetonato)zirconium, mono-t-butoxy.tris(acetylacetonato)zirconium, tetrakis(acetylacetonato)zirconium, triethoxy.mono(ethylacetoacetate)zirconium, tri-n-propoxy.mono(ethylacetoacetate)zirconium, tri-i-propoxy.mono(ethylacetoacetate)zirconium, tri-n-butoxy.mono(ethylacetoacetate)zirconium, tri-sec-butoxy.mono(ethylacetoacetate)zirconium, tri-t-butoxy.mono(ethylacetoacetate)zirconium, diethoxy.bis(ethylacetoacetate)zirconium, di-n-propoxy.bis(ethylacetoacetate)zirconium, di-i-propoxy.bis(ethylacetoacetate)zirconium, di-n-butoxy.bis(ethylacetoacetate)zirconium, di-sec-butoxy.bis(ethylacetoacetate)zirconium, di-t-butoxy.bis(ethylacetoacetate)zirconium, monoethoxy.tris(ethylacetoacetate)zirconium, mono-n-propoxy.tris(ethylacetoacetate)zirconium, mono-i-propoxy.tris(ethylacetoacetate)zirconium, mono-n-butoxy.tris(ethylacetoacetate)zirconium, mono-sec-butoxy.tris(ethylacetoacetate)zirconium, mono-t-butoxy.tris(ethylacetoacetate)zirconium, tetrakis(ethylacetoacetate)zirconium, mono(acetylacetonato)tris(ethylacetoacetate)zirconium, bis(acetylacetonato)bis(ethylacetoacetate)zirconium and tris(acetylacetonato)mono(ethylacetoacetate)zirconium; and aluminum chelate compounds such as tris(acetylacetonato)aluminum and tris(ethylacetoacetate)aluminum.
The organic acids include, for example, acetic acid, propionic acid, butanoic acid, pentanoic acid, hexanoic acid, heptanoic acid, octanoic acid, nonanoic acid, decanoic acid, oxalic acid, maleic acid, methylmalonic acid, adipic acid, sebacic acid, gallic acid, butyric acid, mellitic acid, arachidonic acid, 2-ethylhexanoic acid, oleic acid, stearic acid, linoleic acid, linolenic acid, salicylic acid, benzoic acid, p-aminobenzoic acid, p-toluenesulfonic acid, benzenesulfonic acid, monochloroacetic acid, dichloroacetic acid, trichloroacetic acid, trifluoroacetic acid, formic acid, malonic acid, sulfonic acid, phthalic acid, fumaric acid, citric acid and tartaric acid. Oxalic acid and maleic acid are particularly preferred.
The inorganic acids include, for example, hydrochloric acid, nitric acid, sulfuric acid, hydrofluoric acid and phosphoric acid.
The organic bases include, for example, pyridine, pyrrole, piperazine, pyrrolidine, piperidine, picoline, trimethylamine, triethylamine, monoethanolamine, di-ethanolamine, dimethylmonoethanolamine, monomethyldi-ethanolamine, triethanolamine, diazabicyclooctane, diaza-bicyclononane, diazabicycloundecene and tetramethylammonium hydroxide.
The inorganic bases include, for example, ammonia, sodium hydroxide, potassium hydroxide, barium hydroxide and calcium hydroxide. Of these catalysts, the metal chelate compounds, the organic acids and the inorganic acids are preferred, and the titanium chelate compounds and the organic acids are more preferred. They may be used either alone or in combination.
The amount of the above-mentioned catalysts used is usually from 0.001 part to 10 parts by weight, and preferably from 0.01 part to 10 parts by weight, based on 100 parts by weight of component (A) (in terms of a completely hydrolyzed and/or condensed product).
In the invention, the acid generating agents include latent thermoacid generating agents and latent photoacid generating agents.
The latent thermoacid generating agents are compounds generating acids by heating them usually to 50xc2x0 C. to 450xc2x0 C., preferably to 200xc2x0 C. to 350xc2x0 C., and onium salts such as sulfonium salts, benzothiazolium salts, ammonium salts and phosphonium salts are used.
Specific examples of the above-mentioned sulfonium salts include alkyl sulfonium salts such as 4-acetophenyldimethylsulfonium hexafluoroantimonate, 4-acetoxyphenyldimethylsulfonium hexafluoroarsenate, dimethyl-4-(benzyloxycarbonyloxy)phenylsulfonium hexafluoroantimonate, dimethyl-4-(benzoyloxy)phenylsulfonium hexafluoroantimonate, dimethyl-4-(benzoyloxy)phenylsulfonium hexafluoroarsenate and dimethyl-3-chloro-4-acetoxyphenylsulfonium hexafluoroantimonate; benzylsulfonium salts such as benzyl-4-hydroxyphenylmethylsulfonium hexafluoroantimonate, benzyl-4-hydroxyphenylmethylsulfonium hexafluorophosphate, 4-acetoxyphenylbenzylmethylsulfonium hexafluoroantimonate, benzyl-4-methylphenylmethylsulfonium hexafluoro-antimonate, benzyl-2-methyl-4-hydroxyphenylmethylsulfonium hexafluoroantimonate, benzyl-3-chloro-4-hydroxyphenylmethylsulfonium hexafluoroarsenate, 4-methoxybenzyl-4-hydroxyphenylmethylsulfonium hexafluorophosphate, benzoin tosylate and 2-nitrobenzyl tosylate; dibenzylsulfonium salts such as dibenzyl-4-hydroxyphenylsulfonium hexafluoroantimonate, dibenzyl-4-hydroxyphenylsulfonium hexafluorophosphate, 4-acetoxyphenyldibenzylsulfonium hexafluoroantimonate, dibenzyl-4-methoxyphenylsulfonium hexafluoroantimonate, dibenzyl-3-chloro-4-hydroxyphenylsulfonium hexafluoroarsenate, dibenzyl-3-methyl-4-hydroxy-5-tert-butylphenylsulfonium hexafluoroantimonate and benzyl-4-methoxybenzyl-4-hydroxyphenylsulfonium hexafluorophosphate; and substituted benzyl sulfonium salts such as p-chlorobenzyl-4-hydroxyphenylmethylsulfonium hexafluoroantimonate, p-nitrobenzyl-4-hydroxyphenylmethylsulfonium hexafluoroantimonate, p-chlorobenzyl-4-hydroxyphenylmethylsulfonium hexafluorophosphate, p-nitrobenzyl-3-methyl-4-hydroxyphenylmethylsulfonium hexafluoroantimonate, 3,5-dichlorobenzyl-4-hydroxyphenylmethylsulfonium hexafluoro-antimonate and o-chlorobenzyl-3-chloro-4-hydroxyphenyl-methylsulfonium hexafluoroantimonate.
Specific examples of the above-mentioned benzothiazonium salts include benzylbenzothiazolium salts such as 3-benzylbenzothiazolium hexafluoroantimonate, 3-benzylbenzothiazolium hexafluorophosphate, 3-benzylbenzothiazolium tetrafluoroborate, 3-(p-methoxybenzyl)benzothiazolium hexafluoroantimonate, 3-benzyl-2-methylthiobenzothiazolium hexafluoroantimonate and 3-benzyl-5-chlorobenzothiazolium hexafluoroantimonate.
Further, as an example of the thermoacid generating agent other than the above, 2,4,4,6-tetrabromocyclohexadienone can be shown.
Of these, 4-acetoxyphenyldimethylsulfonium hexafluoroarsenate, benzyl-4-hydroxyphenylmethylsulfonium hexafluoroantimonate, 4-acetoxyphenylbenzylmethylsulfonium hexafluoroantimonate, dibenzyl-4-hydroxyphenylsulfonium hexafluoroantimonate, 4-acetoxyphenyldibenzylsulfonium hexafluoroantimonate and 3-benzylbenzothiazolium hexafluoroantimonate are preferably used. Commercial products of these compounds include San-Aid SI-L85, SI-L110, SI-L145, SI-L150 and SI-L160 (manufactured by SanShin Chemical Industry Corp.).
These compounds can be used alone or as a combination of two or more of them.
The latent photoacid generating agents used in the invention are compounds generating acids by irradiation of ultraviolet rays usually at 1 mJ to 100 mJ, preferably at 10 mJ to 50 mJ.
The photoacid generating agents include, for example, onium salt photoacid generating agents such as diphenyliodonium trifluoromethanesulfonate, diphenyliodonium pyrenesulfonate, diphenyliodonium dodecylbenzenesulfonate, diphenyliodonium nonafluoro-n-butanesulfonate, bis(4-t-butylphenyl)iodonium trifluoromethanesulfonate, bis(4-t-butylphenyl)iodonium dodecylbenzenesulfonate, bis-(4-t-butylphenyl)iodonium naphthalenesulfonate, bis(4-t-butylphenyl)iodonium hexafluoroantimonate, bis(4-t-butylphenyl)iodonium nonafluoro-n-butanesulfonate, triphenylsulfonium trifluoromethanesulfonate, triphenylsulfonium hexafluoroantimonate, triphenylsulfonium naphthalenesulfonate, triphenylsulfonium nonafluoro-n-butanesulfonate, (hydroxyphenyl)benzenemethylsulfonium toluenesulfonate, cyclohexylmethyl(2-oxocyclohexyl)sulfonium trifluoromethanesulfonate, dicyclohexyl(2-oxocyclohexyl)sulfonium trifluoromethanesulfonate, dimethyl(2-oxocyclohexyl)sulfonium trifluoromethanesulfonate, diphenyliodonium hexafluoroantimonate, triphenylsulfonium camphorsulfonate, (4-hydroxyphenyl)benzylmethylsulfonium toluenesulfonate, 1-naphthyldimethylsulfonium trifluoromethanesulfonate, 1-naphthyldiethylsulfonium trifluoromethanesulfonate, 4-cyano-1-naphthyldimethylsulfonium trifluoromethanesulfonate, 4-nitro-1-naphthyldimethylsulfonium trifluoromethanesulfonate, 4-methyl-1-naphthyldimethylsulfonium trifluoromethane-sulfonate, 4-cyano-1-naphthyldiethylsulfonium trifluoromethanesulfonate, 4-nitro-1-naphthyldiethylsulfonium trifluoromethanesulfonate, 4-methyl-1-naphthyldiethylsulfonium trifluoromethanesulfonate, 4-hydroxy-1-naphthyldimethylsulfonium trifluoromethanesulfonate, 4-hydroxy-1-naphthyltetrahydrothiophenium trifluoromethanesulfonate, 4-methoxy-1-naphthyltetrahydrothiophenium trifluoromethanesulfonate, 4-ethoxy-1-naphthyltetrahydrothiophenium trifluoromethanesulfonate, 4-methoxymethoxy-1-naphthyltetrahydrothiophenium trifluoromethanesulfonate, 4-ethoxymethoxy-1-naphthyltetrahydrothiophenium trifluoromethanesulfonate, 4-(1-methoxyethoxy)-1-naphthyltetrahydrothiophenium trifluoromethanesulfonate, 4-(2-methoxyethoxy)-1-naphthyltetrahydrothiophenium trifluoromethanesulfonate, 4-methoxycarbonyloxy-1-naphthyltetrahydrothiophenium trifluoromethanesulfonate, 4-ethoxycarbonyloxy-1-naphthyltetrahydrothiophenium trifluoromethanesulfonate, 4-n-propoxycarbonyloxy-1-naphthyltetrahydrothiophenium trifluoromethanesulfonate, 4-i-propoxycarbonyloxy-1-naphthyltetrahydrothiophenium trifluoromethanesulfonate, 4-n-butoxycarbonyloxy-1-naphthyltetrahydrothiophenium trifluoromethanesulfonate, 4-t-butoxycarbonyloxy-1-naphthyltetrahydrothiophenium trifluoromethanesulfonate, 4-(2-tetrahydrofuranyloxy)-1-naphthyltetrahydrothiophenium trifluoromethanesulfonate, 4-(2-tetrahydropyranyloxy)-1-naphthyltetrahydrothiophenium trifluoromethanesulfonate, 4-benzyloxy-1-naphthyltetrahydrothiophenium trifluoromethanesulfonate, 1-(naphthylacetomethyl)tetrahydrothiophenium trifluoromethanesulfonate, diphenyl-4-methoxyphenylsulfonium nonafuloro-n-butanesulfonate, diphenyl-4-methoxyphenylsulfonium trifuloromethanesulfonate, diphenyl-4-methylphenylsulfonium trifuloromethanesulfonate, diphenyl-4-tert-butyl-sulfonium perfluorooctanesulfonate, pyrogallol tristrifluoromethanesulfonate, nitrobenzyl-9,10-diethoxyanthracene-2-sulfonate and N-hydroxysuccin-imide trifluoromethanesulfonate; halogen-containing photoacid generating agents such as phenyl-bis(tri-chloromethyl)-s-triazine, methoxyphenyl-bis(trichloro-methyl)-s-triazine and naphthyl-bis(trichloromethyl)-s-triazine; diazoketone photoacid generating agents such as 1,2-naphthoquinonediazido-4-sulfonyl chloride, 1,2-naphthoquinonediazido-5-sulfonyl chloride and 1,2-naphthoquinonediazido-4-sulfonic ester or 1,2-naphthoquinonediazido-5-sulfonic ester of 2,3,4,4xe2x80x2-tetrabenzophenone; sulfone photoacid generating agents such as 4-trisphenacylsulfone, mesitylphenacylsulfone and bis-(phenylsulfonyl)methane; and sulfonic acid compound photoacid generating agents such as benzoin tosylate, trifluoromethanesulfonylbicyclo-[2,2,1]hepto-5-ene-2,3-dicarbodiimide and 1,8-naphthalenedi-carboxylic acid imide trifluoromethanesulfonate.
They can be used alone or as a combination of two or more of them.
Particularly preferred examples of these acid generating agents include triphenylsulfonium trifluoro-methanesulfonate, triphenylsulfonium nonafluoro-n-butane-sulfonate, diphenyl-4-methoxyphenylsulfonium nonafuloro-n-butanesulfonate, diphenyl-4-methoxyphenylsulfonium trifuloromethanesulfonate, diphenyl-4-methylphenylsulfonium trifuloromethanesulfonate and diphenyl-4-tert-butylsulfonium perfluorooctanesulfonate.
The resist underlayer film composition of the invention comprises component (A) and component (B) dissolved or dispersed in an organic solvent.
The organic solvents used in the invention include, for example, aliphatic hydrocarbon solvents such as n-pentane, i-pentane, n-hexane, i-hexane, n-heptane, i-heptane, 2,2,4-trimethylpentane, n-octane, i-octane, cyclohexane and methylcyclohexane; aromatic hydrocarbon solvents such as benzene, toluene, xylene, ethylbenzene, trimethylbenzene, methylethylbenzene, n-propylbenzene, i-propylbenzene, diethylbenzene, i-butylbenzene, triethylbenzene, di-i-propylbenzene, n-amylnaphthalene and trimethylbenzene; monohydric alcohol solvents such as methanol, ethanol, n-propanol, i-propanol, n-butanol, i-butanol, sec-butanol, t-butanol, n-pentanol, i-pentanol, 2-methylbutanol, sec-pentanol, t-pentanol, 3-methoxybutanol, n-hexanol, 2-methylpentanol, sec-hexanol, 2-ethylbutanol, sec-heptanol, heptanol-3, n-octanol, 2-ethylhexanol, sec-octanol, n-nonyl alcohol, 2,6-dimethylheptanol-4, n-decanol, sec-undecyl alcohol, trimethylnonyl alcohol, sec-tetradecyl alcohol, sec-heptadecyl alcohol, phenol, cyclohexanol, methylcyclohexanol, 3,3,5-trimethylcyclohexanol, benzyl alcohol, phenylmethylcarbinol, diacetone alcohol and cresol; polyhydric alcohol solvents such as ethylene glycol, 1,2-propylene glycol, 1,3-butylene glycol, pentanediol-2,4, 2-methylpentanediol-2,4, hexanediol-2,5, heptanediol-2,4, 2-ethylhexanediol-1,3, diethylene glycol, dipropylene glycol, triethylene glycol, tripropylene glycol and glycerol; ketone solvents such as acetone, methyl ethyl ketone, methyl n-propyl ketone, methyl n-butyl ketone, diethyl ketone, methyl i-butyl ketone, methyl n-pentyl ketone, ethyl n-butyl ketone, methyl n-hexyl ketone, di-i-butyl ketone, trimethylnonanone, cyclohexanone, methylcyclohexanone, 2,4-pentanedione, acetonylacetone, diacetone alcohol, acetophenone and fenchone; ether solvents such as ethyl ether, i-propyl ether, n-butyl ether, n-hexyl ether, 2-ethyl hexyl ether, ethylene oxide, 1,2-propylene oxide, dioxolane, 4-methyldioxolane, dioxane, dimethyldioxane, ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol diethyl ether, ethylene glycol mono-n-butyl ether, ethylene glycol mono-n-hexyl ether, ethylene glycol monophenyl ether, ethylene glycol mono-2-ethylbutyl ether, ethylene glycol dibutyl ether, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, diethylene glycol diethyl ether, diethylene glycol mono-n-butyl ether, diethylene glycol di-n-butyl ether, diethylene glycol mono-n-hexyl ether, ethoxytriglycol, tetraethylene glycol di-n-butyl ether, propylene glycol monomethyl ether, propylene glycol monoethyl ether, propylene glycol monobutyl ether, dipropylene glycol monomethyl ether, dipropylene glycol monoethyl ether, tripropylene glycol monomethyl ether, tetrahydrofuran and 2-methyltetrahydrofuran; ester solvents such as diethyl carbonate, methyl acetate, ethyl acetate, xcex3-butyrolactone, xcex3-valerolactone, n-propyl acetate, i-propyl acetate, n-butyl acetate, i-butyl acetate, sec-butyl acetate, n-pentyl acetate, sec-pentyl acetate, 3-methoxybutyl acetate, methylpentyl acetate, 2-ethylbutyl acetate, 2-ethylhexyl acetate, benzyl acetate, cyclohexyl acetate, methylcyclohexyl acetate, n-nonyl acetate, methyl acetoacetate, ethyl acetoacetate, ethylene glycol monomethyl ether acetate, ethylene glycol monoethyl ether acetate, diethylene glycol monomethyl ether acetate, diethylene glycol monoethyl ether acetate, diethylene glycol mono-n-butyl ether acetate, propylene glycol monomethyl ether acetate, propylene glycol monoethyl ether acetate, propylene glycol monopropyl ether acetate, propylene glycol monobutyl ether acetate, dipropylene glycol monomethyl ether acetate, dipropylene glycol monoethyl ether acetate, glycol diacetate, methoxytriglycol acetate, ethyl propionate, n-butyl propionate, i-amyl propionate, diethyl oxalate, di-n-butyl oxalate, methyl lactate, ethyl lactate, n-butyl lactate, n-amyl lactate, diethyl malonate, dimethyl phthalate and diethyl phthalate; nitrogen-containing solvents such as N-methylformamide, N,N-dimethylformamide, N,N-diethylformamide, acetamide, N-methylacetamide, N,N-dimethylacetamide, N-methylpropionamide and N-methylpyrrolidone; and sulfur-containing solvents such as dimethyl sulfide, diethyl sulfide, thiophene, tetrahydrothiophene, dimethyl sulfoxide, sulfolane and 1,3-propanesultone. They can be used alone or as a mixture of two or more of them.
In the invention, it is particularly preferable to use solvents represented by the following general formula (5):
R8O(R10O)eR9xe2x80x83xe2x80x83(5)
wherein R8 and R9 each independently represent hydrogen atoms or univalent organic groups selected from the group consisting of alkyl groups each having 1 to 4 carbon atoms and CH3COxe2x80x94, R10 represents an alkylene group having 2 to 4 carbon atoms, and e represents an integer of 1 or 2.
Preferred examples of the solvents represented by general formula (5) include propylene glycol monomethyl ether, propylene glycol monoethyl ether, propylene glycol monopropyl ether, propylene glycol monobutyl ether, propylene glycol dimethyl ether, propylene glycol diethyl ether, propylene glycol dipropyl ether, propylene glycol dibutyl ether, dipropylene glycol monomethyl ether, dipropylene glycol monoethyl ether, dipropylene glycol monopropyl ether, dipropylene glycol monobutyl ether, dipropylene glycol dimethyl ether, dipropylene glycol diethyl ether, dipropylene glycol dipropyl ether, dipropylene glycol dibutyl ether, propylene glycol monomethyl ether acetate, propylene glycol monoethyl ether acetate, propylene glycol monopropyl ether acetate, propylene glycol monobutyl ether acetate, dipropylene glycol monomethyl ether acetate, dipropylene glycol monoethyl ether acetate, dipropylene glycol monopropyl ether acetate, dipropylene glycol monobutyl ether acetate, propylene glycol diacetate, dipropylene glycol diacetate and propylene glycol. Propylene glycol monomethyl ether, propylene glycol monoethyl ether, propylene glycol monopropyl ether, propylene glycol monoisopropyl ether, propylene glycol monobutyl ether, propylene glycol dimethyl ether, propylene glycol diethyl ether, propylene glycol monomethyl ether acetate, propylene glycol monoethyl ether acetate and propylene glycol monopropyl ether acetate are preferred in respect to the solution storage stability. Particularly preferred are propylene glycol monomethyl ether, propylene glycol monoethyl ether, propylene glycol monopropyl ether, propylene glycol monoisopropyl ether and propylene glycol monobutyl ether. They can be used alone or as a mixture of two or more of them.
The compositions for the resist underlayer films of the invention contain the above-mentioned organic solvent. However, when compound (1) is hydrolyzed and/or partially condensed, similar solvents can be used. In particular, it is preferred that compound (1) is hydrolyzed and/or partially condensed in the presence of the solvents represented by the above-mentioned formula (5).
In the composition of the invention, the content of an alcohol having a boiling point of 100xc2x0 C. or less is preferably 2% by weight or less, and more preferably 1% by weight or less, from the viewpoint of uniformity of a coating film. The alcohol having a boiling point of 100xc2x0 C. or less is sometimes generated in hydrolyzing and/or condensing compound (1). It is therefore preferred that the alcohol is removed by distillation so as to give an alcohol content of 2% by weight or less, preferably 1% by weight or less.
Further, when the composition for the resist underlayer film of the invention is prepared, water is preferably added in an amount of 0.2 part to 10 parts by weight based on 100 parts by weight of the whole composition. When the water content is less than 0.2 part by weight or exceeds 10 parts by weight, the storage stability of the composition is deteriorated in some cases.
Furthermore, the amount of sodium and iron contained in the composition is preferably 20 ppb or less, and particularly preferably 15 ppb or less, from the viewpoint of resolution of the resist. The composition is sometimes contaminated with sodium and iron derived from raw materials used, so that the raw materials are preferably purified by distillation or the like.
The ratio of component (B) used in the composition for the resist underlayer film of the invention is preferably from 1 part to 30 parts by weight, and more preferably from 1 part to 10 parts by weight, based on 100 parts by weight of component (A) (in terms of a completely hydrolyzed and/or condensed product). A component (B) content of less than 1 part by weight results in increased resist patterns having footing, whereas exceeding 30 parts by weight causes an increase in undercut of the resist patterns.
The compositions for the resist underlayer films of the invention may further contain the following components.
xcex2-Diketone
Examples of the xcex2-diketones include acetylacetone, 2,4-hexanedione, 2,4-heptanedione, 3,5-heptanedione, 2,4-octanedione, 3,5-octanedione, 2,4-nonanedione, 3,5-nonanedione, 5-methyl-2,4-hexanedione, 2,2,6,6-tetramethyl-3,5-heptanedione and 1,1,1,5,5,5-hexafluoro-2,4-heptanedione. They may be used alone or in combination.
In the invention, the amount of the xcex2-diketone contained in the composition for film formation is preferably from 1% to 50% by weight, and more preferably from 3% to 30% by weight, based on the whole solvent.
The addition of the xcex2-diketone within such a range gives certain storage stability, and is less likely to deteriorate characteristics such as coating film uniformity of the composition for film formation.
Others
The compositions for film formation obtained in the invention may further contain components such as colloidal silica, colloidal alumina, organic polymers and surfactants.
Colloidal silica is, for example, a dispersion in which high-purity silicic acid anhydride is dispersed in the above-mentioned hydrophilic organic solvent. The mean particle size thereof is usually from 5 xcexcm to 30 xcexcm, and preferably from 10 xcexcm to 20 xcexcm, and the solid content thereof is from about 10% to about 40% by weight. Such colloidal silica includes, for example, Methanol Silica Sol and Isopropanol Silica Sol manufactured by Nissan Chemical Industries Ltd., and Oscal manufactured by Catalysts and Chemicals Industries Co., Ltd.
Colloidal alumina includes Alumina Sol 520, 100 and 200 manufactured by Nissan Chemical Industries Ltd., and Alumina Clear Sol, Alumina Sol 10 and 132 manufactured by Kawaken Fine Chemicals Co., Ltd.
Examples of the organic polymers include compounds having polyalkylene oxide structures, compounds having sugar chain structures, vinylamide polymers, (meth)acrylate compounds, aromatic vinyl compounds, dendrimers, polyimides, polyamic acids, polyarylenes, polyamides, polyquinoxalines, polyoxadiazoles and fluorine polymers.
The surfactants include, for example, noionic surfactants, anionic surfactants, cationic surfactants and amphoteric surfactants, and further silicone surfactants, polyalkylene oxide surfactants and fluorine-containing surfactants.